Effect of electronic properties of Carbon Nanotubes on the Activity, Selectivity and Lifetime of Fischer-Tropsch Co/CNTs Catalysts Fulltext
[ ahmad tavasoli ] - catalysis research engineering laboratory
The effects of electronic properties of inner and outer surfaces of carbon nanotubes CNTs on the deactivation of cobalt. Fischer -tropsch FT catalysts were studied. The comparative characterization of the fresh and used catalysts by TEM,XRD,TPR,BET and H2 chemisorption showed that cobalt re - oxidation , cobalt -support interactions and sintering are the main sources of catalyst deactivation. TEM showed that 480 h continuous FT synthesis increased the average particles size of the particles located inside the pores from 7 to 7.4 nm while the average particles size of the particles located outside of the tubes increased from 11.5 to 25nm.XRD analysis of the used catalyst confirmed cobalt re-oxidation and interatcion between cobalt and CNTs and creation of carbide phases. when the co% conversion and H2O partial pressure in the reactor are high, the deactivation rate is not dependent on the number of the catalyst active sites and is zero order to %CO conversion.
fischer -tropsch, cobalt , cobalt, carbon nanotubes, deactivation, sintering.
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